Method and apparatus for providing a radio module for a computer system

ABSTRACT

A radio module that meets FCC Limited Modular Approval including a wireless transceiver and a low-level baseband controller. Only a portion of the baseband associated with a wireless communication protocol is contained within the controller. The remainder of the baseband may be contained within a host computer system to which the module may be coupled such that, for one embodiment, the module may be selectively operated in accordance with one of multiple wireless communication protocols.

[0001] The present invention relates to computer systems and moreparticularly to a radio module partitioned to meet governmentregulations with protocol flexibility.

BACKGROUND

[0002] Mobile computer systems, from small handheld electronic devicesto application-specific electronic components, such as set-top boxes, tomedium-sized notebook and laptop systems, are becoming increasinglypervasive in our society. Unlike their symmetric multiprocessingcounterparts, such as server, workstation, and high-end desktop systems,mobile computer systems typically include a single, primary, hostprocessor coupled to various peripheral devices. Computer systemdesigners continually strive to provide more features to users withoutsignificantly increasing the cost of the system. Unfortunately, eachadditional feature typically corresponds to additional components addedto the computer system, resulting in increased size and expense.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The present invention is illustrated by way of example and notlimitation in the accompanying figures in which like references indicatesimilar elements and in which:

[0004]FIGS. 1a-d are systems formed in accordance with embodiments ofthe present invention;

[0005]FIG. 2a is a processor formed in accordance with an embodiment ofthe present invention;

[0006]FIG. 2b is a flow chart showing a method of the present invention;and

[0007]FIG. 3 is a computer system formed in accordance with an alternateembodiment of the present invention.

DETAILED DESCRIPTION

[0008] In accordance with one embodiment of the present invention, ascalable interface (referred to herein as a “harmonized interface”) froma host computer system to a wireless radio module is provided. Themodule meets the legal requirements for an intentional radiator but maynot be specific to any given wireless communication protocol. On theother side of the harmonized interface resides a generic protocol enginethat can manipulate the wireless module to meet a given wirelesscommunication protocol. Sitting above the protocol engine resides thenormal operating system (OS) driver stack that then connects to thedifferent networking and peripheral drivers of the host computer system.

[0009] With this type of partitioning, a radio module may be designed tooperate in accordance with multiple wireless communication protocols.The harmonized interface may connect this radio module to a hostcomputer system that then performs the high-level baseband processingfor the module. By dynamically changing the source code in the hostsystem, different wireless communication protocols may be emulated.

[0010] For example a module may be created that that operates inaccordance with the Bluetooth* (as described in, e.g., “Specification ofthe Bluetooth System,” v1.0b, Dec. 1^(st), 1999), HomeRF* SharedWireless Access Protocol (SWAP) (as described in, e.g., “Shared WirelessAccess Protocol (SWAP) Specification” v.1.0, Jan. 5, 1999), and IEEE802.11 (as described in, e.g., “IEEE Std 802.11” 1999Edition) protocols.The protocol may be changed dynamically depending on the environment ofthe user (e.g. on the road, in the office, or at home). In addition tothese short-range wireless communication protocols, long-range wirelesscommunication protocols may also be emulated, such as a Third Generation(3G) cellular communication protocol, given the appropriate moduleattached to the harmonized interface. (*Trademarks and brands are theproperty of their respective owners.)

[0011] By partitioning the baseband correctly, such a design may alsoallow the host processor of the host computer system to perform some ofthe higher level baseband processing. Using the harmonized interface, ahost processor of a computer system may perform baseband processingfunctions natively, thereby reducing the cost of the system by reducingthe need for separate, specialized processing hardware to support theradio module. To perform these functions, the host processor may includeenhancements over conventional processors that enable the host processorto process real-time events, such as those associated with wirelesscommunication protocols.

[0012] A more detailed description of embodiments of the presentinvention, including various configurations and implementations, isprovided below.

[0013] The Wireless Module

[0014] Although much of the following discussion focuses on Bluetoothtechnology, including the Bluetooth baseband, it is to be appreciatedthat the concepts discussed herein may be more broadly applied to nearlyany wireless communication protocol and its respective baseband.

[0015] Current partitioning of a wireless Bluetooth module follows thesilicon technology used for the implementation. The radio frequency (RF)analog portion of a Bluetooth module is typically manufactured using aBI-CMOS process, and resides in one device (e.g. the transceiver). Theremaining micro-controller section is typically manufactured using aCMOS process, and resides in a separate device, referred to herein asthe short range wireless baseband controller.

[0016] The Bluetooth system is based on radio technology. Consequently,compliance with a number of country-specific regulatory requirements maybe important for the success of the Bluetooth protocol. Theserequirements are normally tracked by a government agency, including, forexample, the Federal Communications Commission (FCC) in the UnitedStates and the Ministry of Posts and Telecommunications (MPT) in Japan.Their requirements dictate how a compliant radio is to behave withintheir respective country. After a product to be sold has been assembled,it is sent to a government agency-approved testing facility to be testedand certified. After this testing is complete (which may take two monthsor more) and the product is certified, the product may then be sold inthat country's markets.

[0017] To speed up product introduction of such devices, a processcalled Declaration of Compliance (DoC) has been created. This processallows a company to pre-certify a device based on the fact that it isassembled with pre-tested (and pre-certified) components. Building adevice using a pre-certified component allows a company to self-certifytheir final product through the DoC process. In the United States, toachieve pre-certification of a wireless module, the module may beexpected to meet the requirements of Limited Modular Approval (LMA) asdescribed in the FCC publication entitled “Part 15 Unlicensed ModularTransmitter Approval” published Jun. 26, 2000.

[0018] In accordance with one embodiment of the present invention, aradio module is provided that meets the FCC's LMA requirements such thatan OEM can use the DoC process to self-certify their end-user productsincorporating the module. This removes from the product developmentcycle the FCC radio certification process normally associated withintegrating an intentional RF radiator into a product. Current DoCrequirements for LMA extend up through the equivalent of the BluetoothLink Management Protocol, and because of the present manufacturing-basedpartitioning described above, a radio module, to obtain LMA, may containthe entire Bluetooth baseband.

[0019] For example, consider the computer system of FIG. 1a comprisingprocessor 305, memory 315, and input-output (1-0) device 320 coupled tobus control logic 310 (which is typically the system chipset). Shortrange wireless baseband controller 330 contains the logic associatedwith the full baseband, e.g. the Bluetooth baseband, used to operatetransceiver 335. In other words, baseband controller 330 contains allthe logic used to support the full baseband of a wireless communicationprotocol. In addition, controller 330 contains bus interface logic usedto communicate with bus control logic 310 of the chipset and withtransceiver 335.

[0020] Based on this partitioning, a module that meets the requirementsfor LMA would contain both transceiver 335 and short range wirelessbaseband controller 330 of FIG. 1a. An upgrade or other modification tothe baseband, contained within controller 330, may therefore requirere-certification of such a module. In addition, such a module leaveslittle if any of the baseband processing to be implemented by the hostcomputer system, thereby increasing system costs. Alternatively,integration of controller 330 into the host computer system would causewhat is left-over, transceiver 335, to not be subject to the DoC processbecause it would not meet LMA requirements.

[0021] In accordance with an embodiment of the present invention, shortrange wireless baseband controller 330 of FIG. 1a is split such thatsome of the baseband may be integrated into one or more devices of thehost computer system. The portion of the baseband that is not integratedinto the host system corresponds to the Link Management Protocol,thereby making this portion available, along with the transceiver, tosatisfy LMA of the DoC process.

[0022] For example, consider the computer system of FIG. 1b comprisingprocessor 305, memory 315, and I-O device 320. These elements arecoupled to bus control logic 311. Bus control logic 311 includes anintegrated high-level baseband controller 312 associated with thehigh-level portion of the Bluetooth (or other wireless communicationprotocol) baseband, previously contained within controller 330 of FIG.1a. The remaining low-level portion of the baseband, previouslycontained within controller 330, is now contained within low-levelbaseband controller 331. This controller, along with transceiver 336,now constitutes new radio module 340 in accordance with an embodiment ofthe present invention, and this module is coupled to bus control logic311, containing high-level baseband controller 312, via a harmonizedinterface.

[0023] Radio module 340 of FIG. 1b may be pre-certified by the FCC (oranalogous agencies of foreign countries) using the LMA and DoCprocesses, and sold as an independent, add-on component to computersystem manufacturers for connecting to their systems. In accordance withone embodiment of the present invention, radio module 340 includesexternally accessible I-O ports coupled to I-O buffers within themodule. These interconnects may be designed to be coupled to one or morecomponents of the host computer system to enable communication betweenthe module and the host computer system.

[0024] By designing radio module 340 of FIG. 1b generically, the modulemay support multiple protocols, and each may share some segment of thebaseband portion contained within radio module 340. Protocol-specificbaseband processing is performed in the high-level portion of thebaseband, which is coordinated by high level baseband controller 312integrated into bus control logic 311. Baseband protocol selection andoperation may be controlled, at least in part, by one or more softwareprograms that may or may not involve direct user interaction. Theseprograms may reside, at least in part, on any machine-accessible mediumsuch as a magnetic disk (e.g. a hard drive or floppy disk), an opticaldisk (e.g. a CD or DVD), a semiconductor device (e.g. Flash, EPROM, orRAM), or carrier wave, all of which are collectively represented by I-Odevices 320 of FIGS. 1 a-c.

[0025] In accordance with one embodiment of the present invention, thesingle radio module may run different protocols depending on theenvironment of the user. For example, while traveling a user may use themodule to execute Bluetooth protocols. In the office, the user may usethe module to execute IEEE 802.11 protocols, and at home the user mayuse the module to execute SWAP/Home-RF protocols. In accordance withanother embodiment of the present invention, the module supports otherwireless communication protocols that also operate in the 2.4 GHz band.Alternatively, the module may be modified to support wirelesscommunication protocols that operate in other radio bands.

[0026] In accordance with one embodiment of the present invention,execution of the high-level baseband protocols (baseband processing) isdone by (or aided by) host processor 305 of FIG. 1b, which may bemodified to support real-time event processing as described below.Alternatively, all or a portion of the high-level baseband processingmay be performed by control logic embedded within bus control logic 311.For an alternate embodiment of the present invention, execution of thehigh-level baseband protocols is done by (or aided by) a peripheralcontroller of the host system, as described below in conjunction withFIG. 1c.

[0027] The computer system of FIG. 1c comprises processor 305, memory315, and I-O device 320 coupled via bus control logic 310. In addition,embedded controller 325 is coupled to bus control logic 310. Embeddedcontroller 325 may be, for example, a keyboard controller or long-rangewireless controller. Embedded controller 325 includes high-levelbaseband controller 326 interfacing to radio module 340 via theharmonized interface. The embodiment of the present invention depictedin FIG. 1c may be found advantageous over the embodiment of FIG. 1b inthat the embodiment of FIG. 1c provides for operation of the radiomodule even when the processor may be in a power-down (low power) state.The embodiment of FIG. 1b may be found advantageous in that basebandprocessing by the host processor reduces system cost because it reducesthe need for a separate controller.

[0028] In addition to the features of the radio module described above,the module may include features that enable the module to receive LMAfrom the FCC as an intentional radiator, and its equivalent from othergovernments. For example, in accordance with one embodiment of thepresent invention, the radio module may additionally include its ownreference oscillator, antenna, RF shielding, buffered data inputs, andpower supply regulator.

[0029] In accordance with one embodiment of the present invention, theinterconnect between the radio module and the host system components mayinclude a flexible cable, such as a ribbon cable, that may span sixinches or more. The length of such a cable may be selected to span thedistance from the lid of a notebook or other mobile computer system,through the hinge of the host system to the motherboard for coupling toother components. The radio module, including its antenna, may beadvantageously affixed to the lid.

[0030] For example, FIG. 1d shows notebook computer system 400comprising base 410 coupled to hinged lid 405. In accordance with oneembodiment of the present invention, the motherboard of the computersystem, containing, for example, the processor, chipset (bus controllogic), main memory, and high-level baseband controller, is included inbase 410 of computer system 400. Lid 405 of the computer system includesa display screen. Alternatively, a lid of an alternate computer system,such as a tablet or handheld computer system, may be any protectivecover with or without a display screen or other input/outputfunctionality.

[0031] One advantage to placing radio module 340 in lid 405 of FIG. 1dis that, during normal operation, lid 405 typically exists as thehighest point in the computer system, thereby aiding in wirelesscommunication. As shown, radio module 340 may be affixed within lid 405at location 415, at or near the top of lid 405, with flexible cable 420extending down through lid 405 and through the hinged coupling betweenlid 405 and base 410. The end of cable 420, opposite radio module 340,may then be coupled to components within base 410, such as thehigh-level baseband controller which may be integrated into a chipset ormicro-controller of the motherboard within base 410. Note that radiomodule 340 and cable 420 are shown removed from lid 405 in FIG. 1d forclarity. In accordance with the embodiment described above, the radiomodule and cable are integrated within the lid or otherwise affixed tothe lid.

[0032] Real-Time Event Processing

[0033] Note that as used herein, the term “real-time” is not intended toimply that a host system responds instantaneously to a signal generatedby an external device. Rather, the term “real-time” is intended to implysufficient determinism and sufficiently reliable latency on the part ofthe host system to, for example, reliably enable the establishment andmaintenance of a wireless communication link with an external device.For one embodiment of the present invention, this wireless communicationlink may be in accordance with a Bluetooth or other wirelesscommunication protocol. The external device may be an electronic devicehaving an independent processor that is not under direct control of thehost processor of the host system.

[0034] A primary host processor may be modified to process real-timeevents such as those associated with establishing a wirelesscommunication link with an external device in accordance with aBluetooth or other wireless communication protocol. One manner in whicha conventional host processor may be modified to process these real-timeevents is to include a timer and a high priority event (interrupt)circuit in the host processor. This may enable a real-time kernel to rununderneath an existing operating system that does not have real-timeattributes. An example of an operating system that does not havereal-time attributes includes the Windows* operating systems such asWindows NT, Windows 2000, Windows 98, and Windows ME (MillenniumEdition). (*Trademarks and Brands are the property of their respectiveowners).

[0035] This kernel may set the timer to generate the high priority eventat regular intervals. Upon activation, a real-time event circuit maytransfer control to a real-time event handler (kernel software) whichmay perform a real-time task. This handler may be used to process awireless baseband protocol that has strict timing requirements.Additionally, this method may encompass the use of an event pin whichmay also generate this high priority event. The event pin may be coupledto the processor itself or to an external device coupled to theprocessor, such as a chipset. For an alternate embodiment of the presentinvention, the high priority event may be generated using a status bitstored within the processor or in an external device.

[0036] One feature of this high priority event is that it may providemore reliable latencies over conventional interrupts, reducing the riskof a high priority event latency being upset by other tasks beingperformed by the processor. Hence, in accordance with one embodiment ofthe present invention, this high priority event is one of the highestpriority interrupts in the processor, although other interrupts, such asmay be used for memory error handling, may be of higher priority.

[0037] Hardware and software elements in accordance with an embodimentof the present invention are shown in FIGS. 2a and 2 b, respectively.Host processor 100 includes an interval timer 105 that may be set by asoftware routine. The timer triggers real-time event circuit 110 toimplement the method of FIG. 2b. Alternatively, interval timer 105 maytrigger real-time event circuit 110 to read a register to determine if areal-time event has been received. For another embodiment, hostprocessor 100 includes an externally accessible event pin 115 that maybe used by external devices within the host computer system to triggerreal-time event circuit 110 to implement the method of FIG. 2b.

[0038] In accordance with the embodiment of FIG. 2b, the processor isexecuting a process at step 150 when a real-time event interrupt (REI)occurs at step 155. This REI may be caused by, for example, event timer105 expiring its set time interval or the activation of event pin 115 ofhost processor 100 of FIG. 2a. In response to the REI, real-time eventcircuit 110 causes host processor 100 to halt the process being executedat step 150 and save the processor state at step 160. The processorstate may be saved to a reserved memory space.

[0039] At step 165 of FIG. 2b, host processor 100 calls and executes aREI handler. In accordance with one embodiment of the present invention,this REI handler includes instructions that, when executed by the hostprocessor, cause the host processor to read one or more registers thatstore information related to the real-time event. For example, the hostprocessor may read one or more registers that store informationindicating the presence or absence of a wirelessly transmittedidentification signal from an external device requesting wirelesscommunication.

[0040] If it is determined that an external device is present andrequests communication, the host processor may establish communication(or may establish a schedule for future communication) with the externaldevice at this time. Alternatively, the host processor may, during thistime, perform baseband processing functions in accordance with awireless communication protocol as described above.

[0041] After a REI return instruction is received at step 170 of FIG.2b, the processor state stored in the reserved memory space may berestored to the host processor, and the previous process (exited fromstep 150) may continue. Note that the above-described hardware andsoftware may be implemented either with or without OS support.

[0042] In accordance with an alternate embodiment of the presentinvention, real-time event processing may be implemented via a secondarynon-symmetric processor (NSP) integrated into the primary hostprocessor. For this embodiment, the NSP may execute an OS that supportsreal-time processing separate from the primary OS executed by theprimary host processor, which may not support real-time functionality.In accordance with this embodiment, the NSP may then perform thebaseband processing functions in accordance with a wirelesscommunication protocol, as described above, while the primary processorperforms the regular work of the host processor for the remainder of thecomputer system.

[0043]FIG. 3 includes a host processor 200 formed in accordance with anembodiment of the present invention in which NSP core 210 is integratedwith the primary host processor core 205. In accordance with oneembodiment of the present invention, the NSP core is integrated on thesame semiconductor substrate as the primary host processor core to forma single processor. To reduce cost, primary host processor core 205 andNSP core 210 share L2 cache 215, and both processor cores maycommunicate via bus unit 215 to a shared memory subsystem 220 of thehost computer system. Both cores may additionally share other systemresources.

[0044] In accordance with one embodiment of the present invention, theNSP core and primary host processor core share an instruction setarchitecture (ISA). For an alternate embodiment of the presentinvention, the NSP and primary host processor cores do not share an ISA

[0045] This invention has been described with reference to specificexemplary embodiments thereof. It will, however, be evident to personshaving the benefit of this disclosure that various modifications andchanges may be made to these embodiments without departing from thebroader spirit and scope of the invention. The specification anddrawings are, accordingly, to be regarded in an illustrative rather thana restrictive sense.

What is claimed is:
 1. A component to be coupled to a host computersystem, the component comprising: a wireless transceiver; and alow-level baseband controller having logic associated with only aportion, but not all, of a baseband to operate the transceiver inaccordance with a wireless communication protocol, the portion of thebaseband being sufficient to enable the component to achieve LimitedModular Approval by the Federal Communications Commission.
 2. Thecomponent of claim 1, further comprising buffered, externally accessibleinput-output ports for interconnection to the host computer system. 3.The component of claim 2, further comprising a flexible cable coupled tothe electrical input-output ports.
 4. The component of claim 1, whereina remainder of the baseband not integrated into the component is to beintegrated within the host computer system.
 5. The component of claim 1,wherein the component is to be operated in accordance with a pluralityof wireless communication protocols that share at least a segment of theportion of the baseband.
 6. The component of claim 1, wherein thecomponent is to be operated in accordance with one of a plurality ofwireless communication protocols selected by the host computer system.7. The component of claim 6, wherein the plurality of wirelesscommunication protocols includes Bluetooth, SWAP, and IEEE 802.11. 8.The component of claim 6, wherein the portion of the baseband includes alink management protocol.
 9. The component of claim 8, wherein theportion of the link management protocol is in accordance with aBluetooth wireless communication specification.
 10. The component ofclaim 1, further comprising a reference oscillator, antenna, RFshielding, and a power supply regulator.
 11. A method comprising:providing a mobile, uniprocessor computer system with a high-levelbaseband controller to determine one of a plurality of wirelesscommunication protocols in accordance with which to wirelesslycommunicate; coupling a radio module to the computer system, the radiomodule including a low-level baseband controller and a transceiver toenable wireless communication in accordance with the plurality ofwireless communication protocols, the module meeting Limited ModularApproval by the Federal Communications Commission; and enabling thecomputer system to operate the radio module in accordance with the oneof the plurality of wireless communication protocols by installing anappropriate software program on a machine-accessible medium coupled tothe host computer system.
 12. The method of claim 11, wherein providingthe computer system with the high-level baseband controller includesincorporating a chipset into the computer system that includes thehigh-level baseband controller.
 13. The method of claim 11, whereinproviding the computer system with the high-level baseband controllerincludes incorporating a keyboard controller into the computer systemthat includes the high-level baseband controller.
 14. The method ofclaim 11, wherein coupling the radio module to the computer systemincludes coupling input-output buffers of the radio module to thecomputer system via a flexible cable that enables the radio module to belocated in a lid of the computer system.
 15. A method comprising:enabling a computer system to operate a radio module in accordance witha first wireless communication protocol during a first period of time,the radio module meeting Limited Modular Approval by the FederalCommunications Commission independent of the computer system; andenabling the computer system to operate the radio module in accordancewith a second wireless communication protocol during a second period oftime.
 16. The method of claim 15, wherein enabling the computer systemto operate the radio module includes enabling signals to be transmittedbetween the computer system and the radio module via a flexible cablecoupled to a motherboard of the computer system at a first end andcoupled to the radio module affixed to a lid of the computer system at asecond end.
 17. The method of claim 15, wherein enabling a computersystem to operate a radio module in accordance with a first wirelesscommunication protocol includes enabling a first portion of basebandprocessing associated with the first wireless communication protocol tobe performed by the computer system and enabling a second portion ofbaseband processing associated with the first wireless communicationprotocol to be performed by the radio module.
 18. The method of claim17, wherein the first wireless communication protocol is a Bluetoothprotocol, and the second portion of baseband processing is in accordancewith the Bluetooth link management protocol.
 19. The method of claim 18,wherein the second wireless communication protocol is an IEEE 802.11 orSWAP protocol.
 20. The method of claim 17, wherein enabling the firstportion of baseband processing associated with the first wirelesscommunication protocol to be performed by the computer system includesequipping the computer system with a chipset having an integratedbaseband controller.
 21. The method of claim 15, wherein enabling acomputer system to operate a radio module in accordance with a secondwireless communication protocol includes equipping the computer systemwith a keyboard controller having an integrated baseband controller toperform a first portion of baseband processing associated with thesecond wireless communication protocol, and enabling a second portion ofbaseband processing associated with the second wireless communicationprotocol to be performed by the radio module.
 22. A mobile, uniprocessorcomputer system programmed to implement the method of claim
 15. 23. Amachine-accessible medium including machine-accessible instructionsthat, when executed by a computer system, cause the computer system toperform the method of claim
 15. 24. The medium of claim 23, furthercomprising machine-accessible instructions that, when executed by thecomputer system, cause the computer system to further perform the methodof claim
 17. 25. The medium of claim 23, further comprisingmachine-accessible instructions that, when executed by the computersystem, cause the computer system to further perform the method of claim19.
 26. A mobile, uniprocessor computer system comprising: a radiomodule including buffered input-output ports, a low-level basebandcontroller, and a transceiver to enable wireless communication inaccordance with a plurality of wireless communication protocols, themodule meeting Limited Modular Approval by the Federal CommunicationsCommission; a high-level baseband controller coupled to the input-outputports of the radio module to operate the radio module in accordance witha selected one of the plurality of wireless communication protocols. 27.The computer system of claim 26, further comprising a flexible cablecoupled to the high-level baseband controller at a first end and coupledto the ports of the radio module at a second end.
 28. The computersystem of claim 27, further comprising a hinged lid into which the radiomodule is affixed, the flexible cable extending through a hinge betweenthe radio module and the high-level baseband controller.
 29. Thecomputer system of claim 26, further comprising a chipset, thehigh-level baseband controller being incorporated into the chipset. 30.The computer system of claim 26, further comprising a keyboardcontroller, the high-level baseband controller being incorporated intothe keyboard controller.
 31. The computer system of claim 26, whereinthe plurality of wireless communication protocols includes Bluetooth,SWAP, and IEEE 802.11.
 32. The computer system of claim 26, wherein thelow-level baseband controller includes a baseband portion associatedwith a link management protocol.